Display screen or portion thereof with a graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with a graphical user interface, showing a first embodiment of the new design.

FIG. 2 is an annotated front view of FIG. 1.

FIG. 3 is an enlarged detail view showing the portion “3” indicated in FIG. 2.

FIG. 4 is a front view of a display screen or portion thereof with a graphical user interface, showing a second embodiment thereof.

FIG. 5 is an annotated front view of FIG. 4; and,

FIG. 6 is an enlarged detail view showing the portion “6” indicated in FIG. 5.

The broken line showing of the display screen and remainder of the graphical user interface is environmental and forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a graphical user interface, as shown and described. 